Multiple sources informed Barstool Sports and Us Weekly of the split.
"It had to do with the distance and them barely seeing each other," the unnamed source told Us Weekly. "He got signed to the Miami Dolphins, and Olivia wasn't going to move there."
Amendola deleted all of the photos of Culpo from his Instagram account and unfollowed her over the weekend.
The Dolphins' new addition spent the weekend in Austin, Texas, while Culpo was in Las Vegas.
Culpo's last photo taken with Amendola on Instagram was posted on March 10.
In one of her Instagram story posts, Culpo shared the title of the book she brought with her, titled: Braving the Wilderness: The Quest for True Belonging and the Courage to Stand Alone.
Amendola, 32, signed with the Dolphins in free agency this offseason after spending the last five seasons with the New England Patriots. The nine-year NFL veteran spent the first four years of his career with the St. Louis Rams. Amendola -- a two-time Super Bowl champion -- signed a two-year, $12 million contract with the Dolphins.
Culpo, 25, is from Cranston, R.I. and attended Boston University. Amendola is from The Woodlands, Texas.